Riveting tool and working plunger assembly



July 6, 1954 H. R. FISCHER ET AL RIVETING TOOL AND WORKING PLUNGER ASSEMBLY 2 Sheets-Sheet 1 Original Filed Dec. 13, 1943 INVENTORS AWMIZD [2 fifi)? 1 wig/2 s .1. zazaz/v AY TGRNEY y 6, 1954 H. R. FISCHER ET AL RIVETING TOOL AND WORKING PLUNGER ASSEMBLY 2 Sheets-Sheet 2 Original Filed Dec. 13, 1943 m w m 5 A f WM fin Patented July 6, 1954 RIVETING TOOL AND WORKING PLUNGER ASSEMBLY Howard B. Fischer and James A. Roberts, Utica, N. Y., assignors to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey Application July 8, 1950, Serial No. 172,668, which is a division of application Serial No. 514,068, December 13, 1943. Divided and this application December 29, 1951, Serial No. 264,220

4 Claims. (Cl. 78-48) This invention relates to riveting machines and the like and more particularly to the construction of the riveting tool and working plunger assembly therefor.

. This application is a division of the application of Howard R. Fischer and James A. Rob-' ertsySerial No. 514,068, filed December 13, 1943, relating to compression riveters and now abandoned, and the application of Howard E. Fischer and James A. Roberts, Serial No..172,668, filed July 8, 1950-, on a stroke adjuster for riveting machines.

It is an object of the present invention to provide a riveting tool and. plunger assembly for riveting machines wherein the riveting tool is connected within a socket opening on the lower end of the plunger by means of an attaching rod extending through a central opening in the plungenthat may slide when the riveting tool has become loose thereupon but which is spring urged towards a position to retain the riveting tool fully within the socket opening at all times, so that there is little chance of the threads of the attaching rod being damaged should the riveting tool become loose on the rod when the ma chine is in operation.

It is another object of the invention to provide ariveting tool and plunger assembly for riveting machines wherein the attaching rod for fixing the riveting tool to the plunger is held against rotation within the plunger by a key that also serves to prevent relative rotation between the plunger and the bushing, while the plunger is being worked up and down, the key traveling in a vertical keyway in the bushing.

Other objects of the invention are to provide a riveting tool and working plLmger assembly for riveting machines, which is of simple construction, inexpensive to manufacture, has a minimum number of parts, safe and not easily damaged, compact, durable, rugged and. efficient in operation.

For a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in which:

Figure l is a fragmentaryelevational view of a riveting machine with the frame thereof broken away to show the work plunger and the riveting tool assembly and with the parts of this assem- I bly being broken away and. shown insection;

Fig. 2 is a perspective and exploded view of the upper internal parts of the working plunger;

Fig. 3 is a side elevational view of the top part of a riveting machine employing the riveting tool and working plunger assembly of the present invention;

Fig. 4 is an enlarged transverse sectional view taken on line 4-4 of Fig. 1 and looking in the direction of the arrows thereof;

Fig. 5 is an enlarged transverse sectional View taken on line 5-5 of Fig. 1 at a slightly higher elevation than Fig. 4 and looking in the direction of the arrows thereof.

Referring now particularly to Fig. 3, there is shown a riveting machine 30 which includes a yoke 3| having upper and lower jaws 32 and 33, and supported rigidly upon a column or pedestal 34 that extends upwardly from a base, not shown. The jaws 32 and 33 have considerable length and have great strength, toughness and elasticity, in order to permit the development of a riveting pressure of many tones, with a consequent spreading apart of the jaws 32 and 33, but without spreading the jaws beyond the elastic limit or developing fatigue of the metal thereof.

In the lower jaw 33, there is mounted a stationary rivet supporting tool or anvil arrangement 36 which is adjustable relative thereto to provide different elevations of tool head 36 by adjusting knob I38 and is held in the adjusted position by a locking screw I'll.

The .upper jaw 32 has a riveting tool or set 31 carried by a working plunger 38 and capable of being brought down during the working stroke toward the stationary rivet supporting tool or anvil 36 in the lower jaw 33. The plunger 38 is vertically slidable through vertically spaced upper and lower bushings 39 and 4| within the jaw 32. These bushings 39 and 4| are tightly fitted in a bore 42 in the upper jaw. The plunger 38 works through the lower bushing 4| and has on its lower end a tool socket opening as for receiving the riveting tool or set 31.

A tool anchoring rod 44 runs vertically through bore 38 in the plunger 38 to establish a detachable threaded connection 44' with the riveting tool 31 to retain the tool in the tool socket opening 43. The rod 44 has a shoulder 44" which abuts seat 38 in the plunger bore to hold the rod 44 against downward displacement through the plunger 38 and the riveting tool 3'! tightly home within the socket opening 43.

The upper end of the rod 44 is hollow and enlarged as indicated at 45 and has a plurality of vertically extending slots 45 through diametri extension which projects into a vertically extending guideway 47 of the upper bushing 39. The key 45; thus holds the rod 44 against rotation relative to plunger 38 and the plunger 38 and rod 44 against rotation relative to the bushing 39 when the rivet set 31 is screwed on the lower end of the rod 44. The bushing 39 is locked against rotation in the upper jaw 32 by a set screw 48.

A spring pressed detent element 49 is disposed within the hollow enlargement 45 of the rod 44 that reacts against a reduced portion 46" of the key 46 to urge downwardly the rod 44 and to maintain at all times its lower threaded end projected into the socket opening 43. The reduced portion 46" of the key 46 receives the tapered head 49 of the detent element 49. A compression spring 59 lies within the enlargement 45 of the rod 44 to react against the detent element 49. The rod 44 is thus urged downwardly through the plunger 38. The rod 44 is permitted to rise against the action of compression spring 50 in the event that upward force is applied to the rod 44. The purpose of seating the rod 44 in a resilient manner is to prevent injury to the threaded connection between the rod 44 and the tool set 31 should the tool set become loose thereon at any time when the machine is in use. Should the rivet set 3'! become loose on the rod 44, shoulder 31' of the rivet set 31 during the work stroke, would strike the lower end of the plunger 36 as the rod 44 under pressure can be forced up within the plunger, and without placing any stress on the thread 44 of the rod 44. A collar 5! on the plunger 38 is engaged by a return compression spring 52 that reacts against lower bushing 4| to return the plunger to its raised position.

The yoke jaw 32 extends upwardly at its front end. A transverse bolt 53 connects upper frame 54 at this end of jaw 32. The front end of the frame'54 is closed by a plate 55. A fluid drive cylinder device 56 is connected to the rear end of the frame 54. This cylinder device 56 has a chamber 5'5 and supports a control valve housing 56. Within the upper frame 54 is an operating cam lever 59' pivoted upon a pivot pin 6|. This cam lever has a nose 62 that projects over the upper end of the tool plunger 38.

The cylinder device 56 contains a reciprocal piston structure 63 and a hollow piston rod 64 that is slidable through a seal 65 in front end wall 66 of the cylinder device 56. The forward end of the piston rod 64 receives a shank portion 6'! of a forked roller block 68. The roller block carries upper and lower rollers 69 and 59 that roll over each other so as to relieve the forked block of a large part of the reaction which is transmitted from the cam lever '59 through the rollers 69 and 69' to track rail II and the frame 54 upon the lower roller 69 working against upper edge 59 of the cam lever 59. The forward movement of the piston structure causes the plunger 38 to be depressed with the rivet set 31 to upset the rivet.

As the roller block 68 is forced forward by the piston 63, the latter being driven by fluid under pressure entering chamber 51, the upper roller 69 engaging the rail II and the lower roller 69' engaging the cam lever 59, the roller block will obviously swing the cam lever 59 down progressively and thereby cause the tool plunger 38 to descend with the set 31 toward the riveting tool or dolly 36 in the lower jaw 33 of the yoke 3I. The upper edge 59' of the cam lever 59 is preferably straight, as is shown, so that the nose end of the lever 59 and the plunger 38 are moved first rapidly due to the fast outer travel of the nose 62 when the roller 69 rides on the lever at points near to the pivot GI and then less rapidly, but with a uniform mechanical advantage or speed ratio between the piston 64 and the plunger 38 as the roller 69 proceeds to the nose end 62 of the lever 59. The result is that the pressure on the rivet is uniform throughout the power stroke so long as the air pressure behind the piston 69 is constant. Accordingly within limits variations in the thickness of the metal sheets being operated on, with corresponding variations in the length of the power stroke, will not alter the shape of the headed rivet or the intensity of the force supplied thereto.

The riveting machine is equipped with a stroke indicator device I59 to enable the operator to ascertain the extent of the forward stroke of the piston. This stroke indicator device comprises a tubular guide I 5! fixed to the lower portion of the frame 54 and extending parallel with the direction of travel of the piston. An

' indicator rod I52 has a lower horizontal portion I53 slidably guided by the tubular guide member I5i. The rear end of the rod is bent and provided with a knob I54 accessible from beneath the cylinder I56 for manually withdrawing the indicator rod when the piston is in its rearward position and to prepare the indicator for its next indication. The indicator rod I52 is provided with a vertical portion I55 which will be pushed forwardly by roller block 68 until the piston ceases to move the roller block, with the result that the indicator rod and its knob I54 come to rest in the attained forward position of the rod thereby giving a visual indication of the extent of the movement of the piston and accordingly the downward extent of the plunger 38 and its rivet set 31. The stroke indicator device is described and claimed in a copending application, Serial No. 264,219, filed simultaneously with this application on December 29, 1951.

In order that the stroke of the plunger 38 permits only a minimum distance of the rivet set 37 from the work piece or rivet and to eliminate lost motion, a device which is adjustable is provided for limiting the return stroke of the work plunger 38. This device works in cooperation with the cam lever 59 and is described more in detail and claimed in the above parent ap plication, Serial No. 172,668. Generally, this device comprises a shaft I83 which is journalled in the sides of the U-shaped frame 54 and extends therebetween and which has a forked extension I64 in which is pivoted by a pin I85 2. stroke adjusting lever I86 having a depending handle grip I96. The shaft I 83 carries a cam I82 which is adjusted by the lever I66 as it is swung along a segmental guide I88. Means are provided for holding the lever I66 when it is moved to an adjusted position so that the cam I82 can be retained in its adjusted position. The lever 59 has a hook extension I9I that engages cam I82 so that the lever 59 will be limited in its upward pivotal movement upon the engagement of the hook extension IBI with the cam I82.

It should now be apparent that there has been provided a plunger and rivet set assembly for a riveting machine wherein the rivet set is at all times held within the socket opening 43 of the plunger in, a manner such that upon the rivet set becoming loose from the threads 44' of the rod 44, movement of the rivet set in the socket opening will not at this time destroy the threads since the rod 44 is resiliently held in place under the action of the detent spring 58 and the detent member 49 reacts against the key 46.

It should be further apparent that the rod 44 is held against rotation relative to the plunger and relative to the rivet set 31 as that the rivet will not become loose and the rod 44 and the plunger are held against rotation relative to the bushing 39 and within the upper jaw 32. The extension 46 of the key 46 in a guide way 4? of the bushing permits the vertical adjustment of the plunger 38 while at the same time prohibiting the rotation of the plunger within the law.

While various changes may be made in the detailed construction, it shall be understood that such changes shall be Wi thin the spirit and scope of the present invention as defined by the appended claims.

What is claimed is:

1. In a compression riveter, a frame having an opening therein, a plunger slidable in the frame opening and said plunger having a central bore and a socket opening at its lower end, a rivet set in the socket opening in the lower end of the plunger, said rivet set having a threaded opening, a rod extending longitudinally through the bore in said plunger, the lower end of the rod being threaded and engaging the threaded opening in the rivet set, the upper end of the rod having an enlargement, said plunger having a seat receiving the enlargement of rod whereby the rivet set may be rigidly held against separation from the lower end of the plunger, and

resilient means interposed between the rod and the plunger to urge the rod downwardly in engagement with said seat, whereby in the event of accidental disengagement between the rivet set and rod, the rod is permitted to yield upwardly when the rivet set engages the work, thus avoiding damage to the screw threads of the rod.

2. In a compression riveter, a frame having an opening therein, a plunger slidable in the frame opening and said plunger having a central bore and a socket opening at its lower end, a rivet set in the socket opening in the lower end of .the plunger, said rivet set having a threaded opening, a rod extending longitudinally through the bore in said plunger, the lower end of the rod being threaded and. engaging the threaded opening in the rivet set, the upper end of the rod having an enlargement, said plunger having a seat receiving the enlargement of the rod whereby the rivet set may be rigidly held against separation from the lower end of the plun er and the socket opening thereof and resilient means interposed between the rod and the plunger to urge the rod downwardly in engagement with said seat whereby in the event of accidental disengagement between the rivet set and rod, the rod is permitted to yield upwardly when the plunger strikes the rivet set,

longitudinal slots of the rod, said resilient means being seated in the bore in the rod and interposed between the rod and the transverse pin.

3. In a compression riveter, a frame, a bushing mounted in the frame and having a guideway therein, a, hollow plunger slidable through said bushing, a rod extending longitudinally through the plunger, the lower end of the plunger having a socket opening, a rivet set disposed in the socket opening and having a threaded opening, the lower end of the rod extending into the socket opening and engaging with the thread of the rivet set, said rod having an enlargement thereon and a pin extending transversely through the rod and plunger, one end of the pin having an extension extending into the guideway of the bushing, whereby the rod may be locked against rotation relative to the plunger and the plunger locked against rotation relative to the bushing when the rivetset is screwed into operative position and while permitting vertical adjustment of the plunger in the bushing.

4. In a compression riveter, a frame, vertically aligned bushings mounted in the frame, one of said bushings having a guideway therein, a plunger slidable through said bushings and having a central bore with a seat intermediate its length thereof, said plunger further having a socket opening and diametrically-opposed transverse holes above the seat, a rivet set fitted in said socket opening and having a threaded opening therein, an attaching rod having a seat thereon extending through the central bore of the plunger and having a threaded lower end extending into the socket opening and into the threaded opening of the rivet set, said attaching rod having a hollow enlargement and diametrically opposed longitudinally extending slots, a transverse pin extending through the diametrically opposed transverse holes in the plunger and the diametrically opposed slots of the attaching rod, said transverse pin having an extension extending into the guideway of the bushing, detent means within the hollow enlargement and reacting against said transverse pin to urge the seat of the attaching rod against the seat of the plunger to permit upward movement of the attaching rod upon the rivet set becoming loose therefrom and thereby to prevent damage to the threads of the rod and rivet set.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 265,093 Johnsen Sept. 26, 1882 1,702,569 Olsen Feb. 19, 1924 1,524,927 Hagen Feb. 3, 1925 2,061,660 Kamosis Nov. 24, 1936 2,274,091 Pavlecka et a1 Feb. 24, 1942 

